Field of the Invention
The disclosure relates to an imaging device, an imaging system, and a driving method of an imaging device.
Description of the Related Art
Recently, an imaging device including a comparator for comparing a signal based on a charge generated by a photoelectric converter with a reference signal has been proposed.
According to an imaging device disclosed in FIG. 2 of Japanese Patent Laid-Open No. 2001-223566, one comparator is used as to multiple pixels. Specifically, one pixel has a photoelectric converter 201, a transistor 204 disposed in a current pathway, and a selecting transistor 207 connected serially to the transistor 204. The transistor 204 and selecting transistor 207 that are included in the pixel define a first current pathway block 210. On the other hand, a transistor 213 connected to a reference voltage input terminal and a dummy selecting transistor 214 define a second current pathway block 211. Also, the first current pathway block 210 and second current pathway block 211 define a differential pair. According to the imaging device disclosed in Japanese Patent Laid-Open No. 2001-223566, one second current pathway block 211 is disposed as to multiple first current pathway blocks 210, i.e. as to multiple pixels.